For example, in the case where cylinder blocks of an internal combustion engine and bearing brackets of an electric motor are cast from aluminum using a die casting machine, there has been widely adopted a method of casting the cylinder blocks or the bearing brackets with sleeve-like insert members made of steel being disposed therein so as to form the surfaces of the cylinders on which pistons slide or the surfaces of the bearing brackets on which the bearings are held, in order to enhance mechanical properties such as the strength and wear resistance of the above-mentioned surfaces. In order to cast the cylinder blocks or the bearing brackets with the above-mentioned insert members disposed therein, it is necessary to previously load a movable metal mold with the insert members at predetermined places thereof, the metal molds being in a separated condition.
For this purpose, an apparatus for inserting one or more insert members is proposed to achieve an automation of the loading operation of the insert members, and is known, for example, from JPB-Hei-3-66982.
As shown in FIG. 6, this apparatus for inserting insert members comprises an insert head 61, which is provided with a guide holder 56 for holding an insert member 100 in a detachable and floating way; a air piston-cylinder assembly 60 for moving forward the guide holder 56; and a pusher air piston-cylinder assembly 62 for pushing out the insert member 100 from the guide holder 56 in order to achieve an automation of the loading of the insert members. The insert head 61 is of such a construction that it is transferred to a predetermined position of a movable metal mold by means of a link mechanism and the guide holder is centered by means of a positioning mechanism.
FIG. 7 is a plan view showing an arrangement of the insert head 61 in the case where the mold for casting the cylinder blocks of an internal combustion engine is loaded with the insert members. In order to cast such cylinder blocks with the insert members disposed therein, a pair of insert heads is arranged between a stationary metal mold (not shown) and the movable metal mold 103. In this case, since in the movable metal mold 103 the directions of inserting the insert members intersect with each other in the partial sections 44 and 46 thereof onto which the insert members are to be fitted, the guide holders 56 and 58 are arranged with their positions inclined by angles of C and D so as to correspond to the above-mentioned intersected directions in the movable metal mold 103.
Thus, since casting the cylinder blocks using the die casting machine requires the provision of two pairs of insert holders corresponding to the arrangement of two kinds of cylinders different in the phases of angles, there is a problem of the apparatus becoming large in size and, so, the space occupied by the apparatus correspondingly being increased. Particularly, since the insert head must be carried into and out of the narrow space between the stationary metal mold and the movable metal mold, there is a disadvantage of the insert head having to be carried making a detour to avoid any interference with the parts of the die casting machine.